Image Number 16 for United States Patent #6285310.
An analog/digital converter including an amplifier (1) wired as an integrator, a comparator (2) electrically downstream from the integrator, a time counter (6) which continually counts the pulses of a pulse generator (5), a bistable element (4), and additional circuitry. The bistable element (4) drives the input network of the amplifier (1) with at least one switch (3) in such a way that in one of its two positions ("off" condition) a current I.sub.x proportional to the analog measured value is integrated, and in the other position ("on" condition) a constant reference current I.sub.ref with opposite polarity to the current I.sub.x is integrated in addition to current I.sub.x. The switching of the bistable element from the "off" condition to the "on" condition is controlled by the time counter, and the switching from the "on" condition to the "off" condition (switch-off time) is controlled by the output signal of the comparator, which is generally synchronized with the pulses of the pulse generator. The pulses of the pulse generator (5) are summed to a result during the time the bistable element is in its "on" position. The additional circuitry displaces the switch-off time of the bistable element (4) beyond the time resulting from the above synchronization by a number of pulses of the pulse generator (5) determined by an arithmetic unit (31).
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